Bug 21486: Only fetch the items' barcodes

Bug 21486: Only fetch the items' barcodes

and avoid unecessary processing

Signed-off-by: Colin Campbell <colin.campbell@ptfs-europe.com>
Tested and found correct AU data is returned, and passes QA test tool

Signed-off-by: Alex Buckley <alexbuckley@catalyst.net.nz>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 87c2b4644745b0333fc8211ce89899784dfa6a5e)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>